Intraocular lenses (IOLs) are implanted in patients' eyes either to replace a patient's lens or to complement the patient's lens. An IOL typically includes an optic and haptics. The optic, or lens, corrects the patient's vision typically via refraction or diffraction. Haptics are support structures used to hold the optic in place within the capsular bag of a patient's eye. In some cases, haptics take the form of arms that are coupled to the optic. In some IOLs, the haptics and optic are formed of the same flexible optical material. In order to possess sufficient mechanical strength to hold the optic in place, the haptics for such lenses are frequently significantly thicker than the optic. Stated differently, the volume of the haptics may be relatively high in such IOLs. Alternatively, other IOLs form the haptics from a stiff material such as polymethyl metacrylate (PMMA). The stiff haptics are typically of constant cross-section and attached at a point to the softer optic.
In general, a physician selects an IOL having the appropriate corrective characteristics for the patient. During ophthalmic surgery, often performed for other conditions such as cataracts, the selected IOL is implanted. To do so, the surgeon makes an incision in the capsular bag of the patient's eye. The IOL is inserted through the incision and set in place. The incision is closed after the IOL is in place.
Although the IOLs function acceptably well in most patients, implanting the IOL may have shortcomings. A relatively large incision may be required for IOL implantation. Large incisions are considered to be more invasive and may adversely affect the patient's recovery. For an IOL having PMMA haptics, an incision may be greater than or equal to 2.4 mm in length. Such a large incision is required to accommodate the stiff haptics. In addition, larger incisions may cause surgically induced astigmatism. This is also an undesirable outcome. Further, the transition between the haptic arms and optic may be unstable because of the significant differences in the characteristics of the materials. Thus, the IOL may also be subject to failure during implantation or once in place. For an IOL formed only of a single material, the higher volume haptics as well as the optic may still require a larger incision than is desired.
Accordingly, what is needed is an improved mechanism for implanting an IOL.